Time-Space Dual Adaptive Smooth Particle Hydrodynamics Study With Soil-Water Coupling In Dam-Break

The collapse of a reservoir dam is one of the major engineering disasters,and once it occurs,it will cause incalculable losses.Smooth particle hydrodynamics(SPH)is widely used in dam break research because of its advantages in simulating free surface problems.However,the classic SPH method has always faced the problem of low computational efficiency due to searching for nearest neighbors;To improve this problem,some scholars have proposed the spatial adaptive SPH algorithm,but its split mode can easily introduce errors when simulating large deformation problems,resulting in a decrease in computational accuracy.Therefore,this article adopts a time space adaptive SPH algorithm(T-S ASPH)to apply to the soil water coupling problem of earth rock dam failure,which ensures accuracy while significantly improving computational efficiency.At present,the existing T-S ASPH algorithm has only conducted in-depth research on elastic large deformation problems,and has not studied fluid and solid elastic-plastic problems.Therefore,this article extends the T-S ASPH algorithm to the soil water coupling problem of dam break,and mainly optimizes the algorithm in three aspects:(1)determining different adaptive splitting criteria for the T-S ASPH algorithm in fluid and solid problems;(2)Research and establish an algorithm model for T-S ASPH combined with elastic-plastic constitutive law of soil,and apply this algorithm to the problem of landslide instability and failure;(3)Study the dynamic coupling model of the soil water interface and determine the adaptive mode of the algorithm at the interface to simulate the soil water coupling problem in the overtopping and collapse of an earth rock dam.This article first adopts the T-S ASPH method,combined with the Navier Stokes equation,to determine that the algorithm should use the velocity threshold as the adaptive splitting criterion in fluid problems.It also simulates the evolution process of water flow in the absence and presence of obstacles.The results show that the T-S ASPH algorithm can improve the computational efficiency by 50% while ensuring accuracy in fluid problems.Subsequently,the algorithm was combined with the Durcker-Prager elastic-plastic constitutive model to study the landslide problem of cohesive and non cohesive soil.By simulating and analyzing the process of landslide collapse movement,the causes of landslide damage were explored.Finally,this article conducted in-depth research on the water and soil coupling problem in the overtopping of earth-rock dams.The T-S ASPH algorithm was combined with the dynamic treatment method of the water and soil interface to simulate and analyze the water and soil coupling process of earth-rock dams subjected to water compression and overtopping failure.The results showed that there was basically no particle penetration at the water and soil interface,which can effectively describe the development of equivalent plastic strain generated by water pressure on the earthrock dam body and improve the calculation efficiency by 45%,Through this study,it is possible to determine the failure surface and triggering mechanism of overtopping and collapse of earth-rock dams,which can provide scientific basis for the construction design and protection of the dam body.